Trajectory tracking control of 6-PSS parallel motion simulator based on global fast terminal sliding mode
In response to the uncertainties and time-varying disturbances in the dynamic model of the 6-PSS parallel motion simulator,a robust control strategy based on sliding mode variable structure was proposed.Firstly,the dynamic model of the mechanism was established using the principle of virtual work.The dynamic model indicated that the 6-PSS parallel mechanism was a multivariable system with nonlinear and strongly coupled characteristics.The dynamic model was processed offline to reflect the actual dynamic characteristics of the mechanism and meet the real-time computational requirements of the device.Then,based on the simplified dynamic model,a global fast terminal sliding mode controller(GFTSMC)was designed.The Lyapunov function was employed to analyze the control law,demonstrating the stability of the controller.Finally,the control strategy was applied to the trajectory tracking control of the 6-PSS parallel motion simulator and compared with PD feedforward control and traditional sliding mode control(SMC)through experimental comparison.The research results indicate that,comparing to PD and SMC,GFTSMC reduces the average error by 82.92%and 18.88%respectively,and the standard deviation by 80.03%and 41.73%respectively.Moreover,it is capable of suppressing oscillations,making it an effective and practical robust control scheme for the 6-PSS parallel motion simulator.The research results can provide a theoretical basis for the control and engineering application of the 6-PSS parallel motion simulator.
parallel mechanismdynamic modelingvirtual work principlesliding mode controlLyapunov functionglobal fast terminal sliding mode controller(GFTSMC)
万方数据
维普
